Intermetallic Compounds RETMg2 (RE = La, Pr, Nd; T = Ni, Pd, Pt) with MgCuAl2-type Structure

2011 ◽  
Vol 66 (6) ◽  
pp. 651-653 ◽  
Author(s):  
Marcel Kersting ◽  
Rainer Pöttgen
Keyword(s):  
Intermetallic Compounds ◽  
Type Structure ◽  
Subsequent Annealing ◽  
Crystal Chemical ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Structure Space

The magnesium-rich intermetallic compounds RETMg2 (RE = La, Pr,Nd; T = Ni, Pd, Pt) were obtained by melting of the elements in sealed tantalum ampoules and subsequent annealing. Their structures have been characterized on the basis of powder X-ray diffraction. The RETMg2 phases crystallize with the orthorhombic MgCuAl2-type structure, space group Cmcm. The crystal chemical peculiarities are briefly discussed.

MgCuAl2-type Intermetallics REPdCd2(RE = Ce, Pr, Nd, Sm)

2012 ◽  
Vol 67 (11) ◽  
pp. 1221-1224 ◽  
Author(s):  
Michael Johnscher ◽  
Rainer Pöttgen
Keyword(s):  
Single Crystal ◽  
Intermetallic Compounds ◽  
High Frequency ◽  
Three Dimensional ◽  
Type Structure ◽  
Subsequent Annealing ◽  
Space Group ◽  
X Ray ◽  
Structure Space ◽  
Structure Factors

The cadmium-rich intermetallic compounds REPdCd2 (RE=Ce, Pr, Nd, Sm) were obtained by high-frequency melting of the elements in sealed niobium ampoules and subsequent annealing in muffle furnaces. The REPdCd2 phases crystallize with the orthorhombic MgCuAl2-type structure, space group Cmcm. The structure of NdPdCd2 was refined from single-crystal X-ray diffractometer data: a=421.9(3), b=995.4(7), c=834.5(6) pm, wR=0.0286, 451 structure factors, 16 variables. The palladium and cadmium atoms build up a three-dimensional [PdCd2] network (281 - 283 pm Pd-Cd; 298 - 335 pm Cd-Cd) in which the neodymium atoms fill cavities. They are connected to the [PdCd2] network via shorter Nd-Pd bonds of 286 pm.

The solid solution TbNiIn1−x Ga x

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Myroslava Horiacha ◽  
Galyna Nychyporuk ◽  
Rainer Pöttgen ◽  
Vasyl Zaremba
Keyword(s):  
Solid Solution ◽  
Unit Cell ◽  
Type Structure ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
Structure Space ◽  
Arc Melting

Abstract Phase formation in the solid solution TbNiIn1−x Ga x at 873 K was investigated in the full concentration range by means of powder X-ray diffraction and EDX analysis. The samples were synthesized by arc-melting of the pure metals with subsequent annealing at 873 K for one month. The influence of the substitution of indium by gallium on the type of structure and solubility was studied. The solubility ranges have been determined and changes of the unit cell parameters were calculated on the basis of powder X-ray diffraction data: TbNiIn1–0.4Ga0–0.6 (ZrNiAl-type structure, space group P 6 ‾ 2 m $P‾{6}2m$ , a = 0.74461(8)–0.72711(17) and c = 0.37976(5)–0.37469(8) nm); TbNiIn0.2–0Ga0.8–1.0 (TiNiSi-type structure, space group Pnma, а = 0.68950(11)–0.68830(12), b = 0.43053(9)–0.42974(6), с = 0.74186(10)–0.73486(13) nm). The crystal structures of TbNiGa (TiNiSi type, Pnma, a = 0.69140(5), b = 0.43047(7), c = 0.73553(8) nm, wR2=0.0414, 525 F 2 values, 21 variables), TbNiIn0.83(1)Ga0.17(1) (ZrNiAl type, P 6 ‾ 2 m $P‾{6}2m$ , a = 0.74043(6), c = 0.37789(3) nm, wR2 = 0.0293, 322 F 2 values, 16 variables) and TbNiIn0.12(2)Ga0.88(2) (TiNiSi type, Pnma, a = 0.69124(6), b = 0.43134(9), c = 0.74232(11) nm, wR2 = 0.0495, 516 F 2 values, 21 variables) have been determined. The characteristics of the solid solutions and the variations of the unit cell parameters are briefly discussed.

Rare Earth-rich Cadmium Compounds RE4TCd (T = Ni, Pd, Ir, Pt)

2008 ◽  
Vol 63 (9) ◽  
pp. 1127-1130 ◽  
Author(s):  
Falko M. Schappacher ◽  
Ute Ch. Rodewald ◽  
Rainer Pöttgen
Keyword(s):  
Rare Earth ◽  
Transition Metal ◽  
Single Crystal ◽  
Intermetallic Compounds ◽  
Three Dimensional ◽  
Type Structure ◽  
Space Group ◽  
X Ray ◽  
Structure Space ◽  
Cadmium Compounds

New intermetallic compounds RE4TCd (RE = Y, La-Nd, Sm, Gd-Tm, Lu; T = Ni, Pd, Ir, Pt) were synthesized by melting of the elements in sealed tantalum tubes in a highfrequency furnace. They crystallize with the Gd4RhIn-type structure, space group F 4̄3m, Z = 16. The four gadolinium compounds were characterized by single crystal X-ray diffractometer data: a = 1361.7(1) pm, wR2 = 0.062, 456 F2 values, 19 variables for Gd4NiCd; a = 1382.1(2) pm, wR2 = 0.077, 451 F2 values, 19 variables for Gd4PdCd; a = 1363.6(2) pm, wR2 = 0.045, 494 F2 values, 19 variables for Gd4IrCd; a = 1379.0(1) pm, wR2 = 0.045, 448 F2 values, 19 variables for Gd4PtCd. The rare earth atoms build up transition metal-centered trigonal prisms which are condensed via common corners and edges, leading to three-dimensional adamantane-related networks. The cadmium atoms form Cd4 tetrahedra which fill voids left in the prisms’ network.

Ternary Bismuthides Li3REBi2 (RE=Ce, Pr, Sm, Gd) with Li3LaSb2- type Structure

2014 ◽  
Vol 69 (9-10) ◽  
pp. 1050-1052 ◽  
Author(s):  
Florian Winter ◽  
Rainer Pöttgen
Keyword(s):  
Type Structure ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Structure Space

Abstract The ternary lithium bismuthides Li3REBi2 (RE=Ce, Pr, Sm, Gd) were synthesized from the elements in sealed niobium ampoules and characterized by powder X-ray diffraction. They crystallize with the Li3LaSb2-type structure, space group P3̅m1

Kristallstrukturen von Li6MgBr8 und Li2MgBr4/Crystal Structure of Li6MgBr8 and Li2MgBr4

1993 ◽  
Vol 48 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Michael Schneider ◽  
Peter Kuske ◽  
Heinz Dieter Lutz
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Type Structure ◽  
Ionic Conductors ◽  
X Ray Diffraction ◽  
Lithium Ions ◽  
Space Group ◽  
X Ray ◽  
Structure Space ◽  
High Temperature Polymorph

The crystal structures of the fast ionic conductors Li6MgBr8 and Li2MgBr4 oC 14 and cF 56 were determined by single crystal X -ray diffraction and neutron powder studies, respectively. At ambient temperature, Li6MBr8 (M = Mg, Mn) crystallize in a Suzuki-type structure (space group Fm3̄̄̄ m , Z = 4, Li6MgBr8: a = 1098.0(1) pm, 114 unique reflections, R = 0.037). Li2MgBr4 oC 14 crystallizes in a SnMn2S4-type structure (space group Cmmm , Z = 2, a = 777.94(2), b = 1104.25(4), and c = 386.55(1) pm , RI, = 0.073, 318 K), the high-temperature polymorph (HTM I) in the Li2MnBr4 cF 56 type (space group Fd 3 m , Z = 8, a = 1124.55(4) pm , RI , = 0.052, 673 K). These structure types are more or less ordered NaCl superstructures. The thermal ellipsoids of the lithium ions are discussed in terms of the conduction pathways and the order-disorder phase transitions observed.

Indides RE3T2In4 (RE = Y, Gd–Tm, Lu; T = Ni, Ru, Rh) with a ZrNiAl superstructure

2016 ◽  
Vol 71 (12) ◽  
pp. 1261-1267 ◽  
Author(s):  
Birgit Heying ◽  
Oliver Niehaus ◽  
Ute Ch. Rodewald ◽  
Rainer Pöttgen
Keyword(s):  
Rare Earth ◽  
Transition Metal ◽  
Transition Metals ◽  
Single Crystal ◽  
Symmetry Reduction ◽  
Type Structure ◽  
Crystal Chemical ◽  
Space Group ◽  
X Ray ◽  
Structure Space

AbstractThree series of rare earth-transition metal-indides RE3T2In4 (RE=Y, Gd–Tm, Lu; T=Ni, Ru, Rh) were synthesized from arc-melted RE3T2 precursor compounds and indium tear shot in sealed niobium ampoules using different annealing sequences. The new indides crystallize with the hexagonal Lu3Co2In4-type structure, space group P6̅. All samples were characterized on the basis of Guinier powder patterns and six structures were refined from single crystal X-ray diffractometer data. The RE3T2In4 structures are derived from the ZrNiAl type through RE/In ordering, paralleled by a symmetry reduction from P6̅2m to P6̅. This induces twinning for some of the investigated crystals. The main crystal chemical motifs of the RE3T2In4 structures are trigonal prisms of rare earth, respectively indium atoms that are filled by the transition metals.

Crystal structure of LnCuSn (Ln = Nd, Sm, Gd)

1998 ◽  
Vol 213 (10) ◽  
Author(s):  
J. V. Pacheco ◽  
K. Yvon ◽  
E. Gratz
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Type Structure ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Structure Space

AbstractThe title compounds were reinvestigated by single crystal X-ray diffraction. They crystallize with the ordered NdPtSb type structure (space group

scholarly journals CRYSTAL STRUCTURE OF THE NEW SILICIDE Lu3Ni11.74(2)Si4

2020 ◽  
Vol 86 (5) ◽  
pp. 3-12
Author(s):  
Bohdana Belan ◽  
Mykola Manyako ◽  
Mariya Dzevenko ◽  
Dorota Kowalska ◽  
Roman Gladyshevskii
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Type Structure ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Arc Melting ◽  
Pearson Symbol ◽  
Ternary Silicide

The new ternary silicide Lu3Ni11.74(2)Si4 was synthesized from the elements by arc-melting and its crystal structure was determined by the single-crystal X-ray diffraction. The compound crystallizes in the Sc3Ni11Ge4-type: Pearson symbol hP37.2, space group P63/mmc (No. 194), a = 8.0985(16), c = 8.550(2) Å, Z = 2; R = 0.0244, wR = 0.0430 for 244 reflections. The silicide Lu3Ni11.74(2)Si4 is new member of the EuMg5.2-type structure family.

X-ray powder diffraction data for ω and C2 phases of Al–Cu–Ir

2008 ◽  
Vol 23 (4) ◽  
pp. 356-359 ◽  
Author(s):  
B. Grushko ◽  
D. Pavlyuchkov
Keyword(s):  
Powder Diffraction ◽  
Diffraction Data ◽  
Tetragonal Structure ◽  
Powder Diffraction Data ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Structure Space ◽  
Cubic Structure

Ternary Al–Cu–Ir phases, isostructural to the Al–Cu–Rh ω and C2 phases, were found to be around the Al70Cu20Ir10 and Al60Cu15Ir25 compositions, respectively. Using powder X-ray diffraction, the former was found to have a tetragonal structure (space group P4/mnc) with a=6.4142(9) Å and c=14.842(4) Å, and the latter has a cubic structure (space group Fm3) with a=15.3928(6) Å.

Crystal structure of mechanochemically prepared Ag2FeGeS4

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Eva M. Heppke ◽  
Shamini Mahadevan ◽  
Thomas Bredow ◽  
Martin Lerch
Keyword(s):  
Density Functional ◽  
Type Structure ◽  
Rietveld Refinements ◽  
Space Group ◽  
X Ray ◽  
Structure Space ◽  
Solid State Route ◽  
Wyckoff Position ◽  
Structure Evaluation ◽  
Hybrid Density Functional

Abstract Ag2FeGeS4 was synthesized as a phase-pure and highly crystalline product by mechanochemical milling from the binary sulfides and iron metal, followed by annealing in H2S atmosphere. The structure evaluation was carried out using X-ray powder diffraction with subsequent Rietveld refinements. As Fe and Ge atoms are not distinguishable using conventional X-ray methods, the chalcopyrite-type structure (space group I 4 ‾ 2 d $I‾{4}2d$ ), exhibiting a statistical distribution of Fe and Ge on Wyckoff position 4b, was considered. However, quantum-chemical calculations at hybrid density-functional level indicate that mechanochemically prepared Ag2FeGeS4 crystallizes in the kesterite-type structure (space group I 4 ‾ $I‾{4}$ ) where the cations are arranged in an ordered way. Ag2FeGeS4 is a further example of a mechanochemically prepared compound differing structurally from the commonly known polymorph exhibiting the stannite type (solid-state route).

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